An escalator is a moving staircase—a conveyor transport device for carrying people between floors of a building. The device consists of a motor-driven chain of individual, linked steps that move up or down on tracks, allowing the step treads to remain horizontal. Modern escalators have single-piece aluminium or stainless steel steps that move on a system of tracks in a continuous loop.
It is to be appreciated that conventionally the steps of an escalator are solid, one piece, die-cast aluminium or steel. In most escalator models manufactured after 1950, both the riser and the tread of each step is cleated (given a ribbed appearance) with comb-like protrusions that mesh with the comb-plates on the top and bottom platforms and the succeeding steps in the chain. Seeberger- or “step-type” escalators featured flat treads and smooth risers; other escalator models have cleated treads and smooth risers. The steps are linked by a continuous metal chain that forms a closed loop. The front and back edges of the steps are each connected to two wheels. The rear wheels are set further apart to fit into the back track and the front wheels have shorter axles to fit into the narrower front track. As such, it is to be appreciated that the cleated feature of the steps is essential for the proper functioning of the escalator.
It is further to be appreciated that the escalators are generally positioned so as to be easily seen and accessible by the general public. As such, escalators, and more particularly the steps of escalators, are prime positions on which to place advertising material as it is sure to be received by a wide audience.
However, due to the cleated design of the majority of the steps of escalators, the placing of advertising material on these steps is often regarded as an onerous and cumbersome process. The advertising material which is so placed should meet the further requirement of not interfering with the proper functioning of the escalator.